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11#include <linux/capability.h>
12#include <linux/export.h>
13#include <linux/sched.h>
14#include <linux/sched/mm.h>
15#include <linux/sched/coredump.h>
16#include <linux/sched/task.h>
17#include <linux/errno.h>
18#include <linux/mm.h>
19#include <linux/highmem.h>
20#include <linux/pagemap.h>
21#include <linux/ptrace.h>
22#include <linux/security.h>
23#include <linux/signal.h>
24#include <linux/uio.h>
25#include <linux/audit.h>
26#include <linux/pid_namespace.h>
27#include <linux/syscalls.h>
28#include <linux/uaccess.h>
29#include <linux/regset.h>
30#include <linux/hw_breakpoint.h>
31#include <linux/cn_proc.h>
32#include <linux/compat.h>
33#include <linux/sched/signal.h>
34#include <linux/minmax.h>
35
36#include <asm/syscall.h>
37
38
39
40
41
42
43int ptrace_access_vm(struct task_struct *tsk, unsigned long addr,
44 void *buf, int len, unsigned int gup_flags)
45{
46 struct mm_struct *mm;
47 int ret;
48
49 mm = get_task_mm(tsk);
50 if (!mm)
51 return 0;
52
53 if (!tsk->ptrace ||
54 (current != tsk->parent) ||
55 ((get_dumpable(mm) != SUID_DUMP_USER) &&
56 !ptracer_capable(tsk, mm->user_ns))) {
57 mmput(mm);
58 return 0;
59 }
60
61 ret = __access_remote_vm(mm, addr, buf, len, gup_flags);
62 mmput(mm);
63
64 return ret;
65}
66
67
68void __ptrace_link(struct task_struct *child, struct task_struct *new_parent,
69 const struct cred *ptracer_cred)
70{
71 BUG_ON(!list_empty(&child->ptrace_entry));
72 list_add(&child->ptrace_entry, &new_parent->ptraced);
73 child->parent = new_parent;
74 child->ptracer_cred = get_cred(ptracer_cred);
75}
76
77
78
79
80
81
82
83static void ptrace_link(struct task_struct *child, struct task_struct *new_parent)
84{
85 __ptrace_link(child, new_parent, current_cred());
86}
87
88
89
90
91
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111
112
113
114
115
116void __ptrace_unlink(struct task_struct *child)
117{
118 const struct cred *old_cred;
119 BUG_ON(!child->ptrace);
120
121 clear_task_syscall_work(child, SYSCALL_TRACE);
122#if defined(CONFIG_GENERIC_ENTRY) || defined(TIF_SYSCALL_EMU)
123 clear_task_syscall_work(child, SYSCALL_EMU);
124#endif
125
126 child->parent = child->real_parent;
127 list_del_init(&child->ptrace_entry);
128 old_cred = child->ptracer_cred;
129 child->ptracer_cred = NULL;
130 put_cred(old_cred);
131
132 spin_lock(&child->sighand->siglock);
133 child->ptrace = 0;
134
135
136
137
138 task_clear_jobctl_pending(child, JOBCTL_TRAP_MASK);
139 task_clear_jobctl_trapping(child);
140
141
142
143
144
145 if (!(child->flags & PF_EXITING) &&
146 (child->signal->flags & SIGNAL_STOP_STOPPED ||
147 child->signal->group_stop_count)) {
148 child->jobctl |= JOBCTL_STOP_PENDING;
149
150
151
152
153
154
155
156
157 if (!(child->jobctl & JOBCTL_STOP_SIGMASK))
158 child->jobctl |= SIGSTOP;
159 }
160
161
162
163
164
165
166
167 if (child->jobctl & JOBCTL_STOP_PENDING || task_is_traced(child))
168 ptrace_signal_wake_up(child, true);
169
170 spin_unlock(&child->sighand->siglock);
171}
172
173static bool looks_like_a_spurious_pid(struct task_struct *task)
174{
175 if (task->exit_code != ((PTRACE_EVENT_EXEC << 8) | SIGTRAP))
176 return false;
177
178 if (task_pid_vnr(task) == task->ptrace_message)
179 return false;
180
181
182
183
184
185 return true;
186}
187
188
189static bool ptrace_freeze_traced(struct task_struct *task)
190{
191 bool ret = false;
192
193
194 if (task->jobctl & JOBCTL_LISTENING)
195 return ret;
196
197 spin_lock_irq(&task->sighand->siglock);
198 if (task_is_traced(task) && !looks_like_a_spurious_pid(task) &&
199 !__fatal_signal_pending(task)) {
200 WRITE_ONCE(task->__state, __TASK_TRACED);
201 ret = true;
202 }
203 spin_unlock_irq(&task->sighand->siglock);
204
205 return ret;
206}
207
208static void ptrace_unfreeze_traced(struct task_struct *task)
209{
210 if (READ_ONCE(task->__state) != __TASK_TRACED)
211 return;
212
213 WARN_ON(!task->ptrace || task->parent != current);
214
215
216
217
218
219 spin_lock_irq(&task->sighand->siglock);
220 if (READ_ONCE(task->__state) == __TASK_TRACED) {
221 if (__fatal_signal_pending(task))
222 wake_up_state(task, __TASK_TRACED);
223 else
224 WRITE_ONCE(task->__state, TASK_TRACED);
225 }
226 spin_unlock_irq(&task->sighand->siglock);
227}
228
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244
245
246static int ptrace_check_attach(struct task_struct *child, bool ignore_state)
247{
248 int ret = -ESRCH;
249
250
251
252
253
254
255
256
257 read_lock(&tasklist_lock);
258 if (child->ptrace && child->parent == current) {
259 WARN_ON(READ_ONCE(child->__state) == __TASK_TRACED);
260
261
262
263
264 if (ignore_state || ptrace_freeze_traced(child))
265 ret = 0;
266 }
267 read_unlock(&tasklist_lock);
268
269 if (!ret && !ignore_state) {
270 if (!wait_task_inactive(child, __TASK_TRACED)) {
271
272
273
274
275
276 WARN_ON(READ_ONCE(child->__state) == __TASK_TRACED);
277 ret = -ESRCH;
278 }
279 }
280
281 return ret;
282}
283
284static bool ptrace_has_cap(struct user_namespace *ns, unsigned int mode)
285{
286 if (mode & PTRACE_MODE_NOAUDIT)
287 return ns_capable_noaudit(ns, CAP_SYS_PTRACE);
288 return ns_capable(ns, CAP_SYS_PTRACE);
289}
290
291
292static int __ptrace_may_access(struct task_struct *task, unsigned int mode)
293{
294 const struct cred *cred = current_cred(), *tcred;
295 struct mm_struct *mm;
296 kuid_t caller_uid;
297 kgid_t caller_gid;
298
299 if (!(mode & PTRACE_MODE_FSCREDS) == !(mode & PTRACE_MODE_REALCREDS)) {
300 WARN(1, "denying ptrace access check without PTRACE_MODE_*CREDS\n");
301 return -EPERM;
302 }
303
304
305
306
307
308
309
310
311
312
313
314 if (same_thread_group(task, current))
315 return 0;
316 rcu_read_lock();
317 if (mode & PTRACE_MODE_FSCREDS) {
318 caller_uid = cred->fsuid;
319 caller_gid = cred->fsgid;
320 } else {
321
322
323
324
325
326
327
328
329 caller_uid = cred->uid;
330 caller_gid = cred->gid;
331 }
332 tcred = __task_cred(task);
333 if (uid_eq(caller_uid, tcred->euid) &&
334 uid_eq(caller_uid, tcred->suid) &&
335 uid_eq(caller_uid, tcred->uid) &&
336 gid_eq(caller_gid, tcred->egid) &&
337 gid_eq(caller_gid, tcred->sgid) &&
338 gid_eq(caller_gid, tcred->gid))
339 goto ok;
340 if (ptrace_has_cap(tcred->user_ns, mode))
341 goto ok;
342 rcu_read_unlock();
343 return -EPERM;
344ok:
345 rcu_read_unlock();
346
347
348
349
350
351
352
353
354
355 smp_rmb();
356 mm = task->mm;
357 if (mm &&
358 ((get_dumpable(mm) != SUID_DUMP_USER) &&
359 !ptrace_has_cap(mm->user_ns, mode)))
360 return -EPERM;
361
362 return security_ptrace_access_check(task, mode);
363}
364
365bool ptrace_may_access(struct task_struct *task, unsigned int mode)
366{
367 int err;
368 task_lock(task);
369 err = __ptrace_may_access(task, mode);
370 task_unlock(task);
371 return !err;
372}
373
374static int ptrace_attach(struct task_struct *task, long request,
375 unsigned long addr,
376 unsigned long flags)
377{
378 bool seize = (request == PTRACE_SEIZE);
379 int retval;
380
381 retval = -EIO;
382 if (seize) {
383 if (addr != 0)
384 goto out;
385 if (flags & ~(unsigned long)PTRACE_O_MASK)
386 goto out;
387 flags = PT_PTRACED | PT_SEIZED | (flags << PT_OPT_FLAG_SHIFT);
388 } else {
389 flags = PT_PTRACED;
390 }
391
392 audit_ptrace(task);
393
394 retval = -EPERM;
395 if (unlikely(task->flags & PF_KTHREAD))
396 goto out;
397 if (same_thread_group(task, current))
398 goto out;
399
400
401
402
403
404
405 retval = -ERESTARTNOINTR;
406 if (mutex_lock_interruptible(&task->signal->cred_guard_mutex))
407 goto out;
408
409 task_lock(task);
410 retval = __ptrace_may_access(task, PTRACE_MODE_ATTACH_REALCREDS);
411 task_unlock(task);
412 if (retval)
413 goto unlock_creds;
414
415 write_lock_irq(&tasklist_lock);
416 retval = -EPERM;
417 if (unlikely(task->exit_state))
418 goto unlock_tasklist;
419 if (task->ptrace)
420 goto unlock_tasklist;
421
422 if (seize)
423 flags |= PT_SEIZED;
424 task->ptrace = flags;
425
426 ptrace_link(task, current);
427
428
429 if (!seize)
430 send_sig_info(SIGSTOP, SEND_SIG_PRIV, task);
431
432 spin_lock(&task->sighand->siglock);
433
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449
450
451 if (task_is_stopped(task) &&
452 task_set_jobctl_pending(task, JOBCTL_TRAP_STOP | JOBCTL_TRAPPING))
453 signal_wake_up_state(task, __TASK_STOPPED);
454
455 spin_unlock(&task->sighand->siglock);
456
457 retval = 0;
458unlock_tasklist:
459 write_unlock_irq(&tasklist_lock);
460unlock_creds:
461 mutex_unlock(&task->signal->cred_guard_mutex);
462out:
463 if (!retval) {
464
465
466
467
468
469
470
471 wait_on_bit(&task->jobctl, JOBCTL_TRAPPING_BIT, TASK_KILLABLE);
472 proc_ptrace_connector(task, PTRACE_ATTACH);
473 }
474
475 return retval;
476}
477
478
479
480
481
482
483
484static int ptrace_traceme(void)
485{
486 int ret = -EPERM;
487
488 write_lock_irq(&tasklist_lock);
489
490 if (!current->ptrace) {
491 ret = security_ptrace_traceme(current->parent);
492
493
494
495
496
497 if (!ret && !(current->real_parent->flags & PF_EXITING)) {
498 current->ptrace = PT_PTRACED;
499 ptrace_link(current, current->real_parent);
500 }
501 }
502 write_unlock_irq(&tasklist_lock);
503
504 return ret;
505}
506
507
508
509
510static int ignoring_children(struct sighand_struct *sigh)
511{
512 int ret;
513 spin_lock(&sigh->siglock);
514 ret = (sigh->action[SIGCHLD-1].sa.sa_handler == SIG_IGN) ||
515 (sigh->action[SIGCHLD-1].sa.sa_flags & SA_NOCLDWAIT);
516 spin_unlock(&sigh->siglock);
517 return ret;
518}
519
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531
532
533
534
535static bool __ptrace_detach(struct task_struct *tracer, struct task_struct *p)
536{
537 bool dead;
538
539 __ptrace_unlink(p);
540
541 if (p->exit_state != EXIT_ZOMBIE)
542 return false;
543
544 dead = !thread_group_leader(p);
545
546 if (!dead && thread_group_empty(p)) {
547 if (!same_thread_group(p->real_parent, tracer))
548 dead = do_notify_parent(p, p->exit_signal);
549 else if (ignoring_children(tracer->sighand)) {
550 __wake_up_parent(p, tracer);
551 dead = true;
552 }
553 }
554
555 if (dead)
556 p->exit_state = EXIT_DEAD;
557 return dead;
558}
559
560static int ptrace_detach(struct task_struct *child, unsigned int data)
561{
562 if (!valid_signal(data))
563 return -EIO;
564
565
566 ptrace_disable(child);
567
568 write_lock_irq(&tasklist_lock);
569
570
571
572
573 WARN_ON(!child->ptrace || child->exit_state);
574
575
576
577
578 child->exit_code = data;
579 __ptrace_detach(current, child);
580 write_unlock_irq(&tasklist_lock);
581
582 proc_ptrace_connector(child, PTRACE_DETACH);
583
584 return 0;
585}
586
587
588
589
590
591void exit_ptrace(struct task_struct *tracer, struct list_head *dead)
592{
593 struct task_struct *p, *n;
594
595 list_for_each_entry_safe(p, n, &tracer->ptraced, ptrace_entry) {
596 if (unlikely(p->ptrace & PT_EXITKILL))
597 send_sig_info(SIGKILL, SEND_SIG_PRIV, p);
598
599 if (__ptrace_detach(tracer, p))
600 list_add(&p->ptrace_entry, dead);
601 }
602}
603
604int ptrace_readdata(struct task_struct *tsk, unsigned long src, char __user *dst, int len)
605{
606 int copied = 0;
607
608 while (len > 0) {
609 char buf[128];
610 int this_len, retval;
611
612 this_len = (len > sizeof(buf)) ? sizeof(buf) : len;
613 retval = ptrace_access_vm(tsk, src, buf, this_len, FOLL_FORCE);
614
615 if (!retval) {
616 if (copied)
617 break;
618 return -EIO;
619 }
620 if (copy_to_user(dst, buf, retval))
621 return -EFAULT;
622 copied += retval;
623 src += retval;
624 dst += retval;
625 len -= retval;
626 }
627 return copied;
628}
629
630int ptrace_writedata(struct task_struct *tsk, char __user *src, unsigned long dst, int len)
631{
632 int copied = 0;
633
634 while (len > 0) {
635 char buf[128];
636 int this_len, retval;
637
638 this_len = (len > sizeof(buf)) ? sizeof(buf) : len;
639 if (copy_from_user(buf, src, this_len))
640 return -EFAULT;
641 retval = ptrace_access_vm(tsk, dst, buf, this_len,
642 FOLL_FORCE | FOLL_WRITE);
643 if (!retval) {
644 if (copied)
645 break;
646 return -EIO;
647 }
648 copied += retval;
649 src += retval;
650 dst += retval;
651 len -= retval;
652 }
653 return copied;
654}
655
656static int ptrace_setoptions(struct task_struct *child, unsigned long data)
657{
658 unsigned flags;
659
660 if (data & ~(unsigned long)PTRACE_O_MASK)
661 return -EINVAL;
662
663 if (unlikely(data & PTRACE_O_SUSPEND_SECCOMP)) {
664 if (!IS_ENABLED(CONFIG_CHECKPOINT_RESTORE) ||
665 !IS_ENABLED(CONFIG_SECCOMP))
666 return -EINVAL;
667
668 if (!capable(CAP_SYS_ADMIN))
669 return -EPERM;
670
671 if (seccomp_mode(¤t->seccomp) != SECCOMP_MODE_DISABLED ||
672 current->ptrace & PT_SUSPEND_SECCOMP)
673 return -EPERM;
674 }
675
676
677 flags = child->ptrace;
678 flags &= ~(PTRACE_O_MASK << PT_OPT_FLAG_SHIFT);
679 flags |= (data << PT_OPT_FLAG_SHIFT);
680 child->ptrace = flags;
681
682 return 0;
683}
684
685static int ptrace_getsiginfo(struct task_struct *child, kernel_siginfo_t *info)
686{
687 unsigned long flags;
688 int error = -ESRCH;
689
690 if (lock_task_sighand(child, &flags)) {
691 error = -EINVAL;
692 if (likely(child->last_siginfo != NULL)) {
693 copy_siginfo(info, child->last_siginfo);
694 error = 0;
695 }
696 unlock_task_sighand(child, &flags);
697 }
698 return error;
699}
700
701static int ptrace_setsiginfo(struct task_struct *child, const kernel_siginfo_t *info)
702{
703 unsigned long flags;
704 int error = -ESRCH;
705
706 if (lock_task_sighand(child, &flags)) {
707 error = -EINVAL;
708 if (likely(child->last_siginfo != NULL)) {
709 copy_siginfo(child->last_siginfo, info);
710 error = 0;
711 }
712 unlock_task_sighand(child, &flags);
713 }
714 return error;
715}
716
717static int ptrace_peek_siginfo(struct task_struct *child,
718 unsigned long addr,
719 unsigned long data)
720{
721 struct ptrace_peeksiginfo_args arg;
722 struct sigpending *pending;
723 struct sigqueue *q;
724 int ret, i;
725
726 ret = copy_from_user(&arg, (void __user *) addr,
727 sizeof(struct ptrace_peeksiginfo_args));
728 if (ret)
729 return -EFAULT;
730
731 if (arg.flags & ~PTRACE_PEEKSIGINFO_SHARED)
732 return -EINVAL;
733
734 if (arg.nr < 0)
735 return -EINVAL;
736
737
738 if (arg.off > ULONG_MAX)
739 return 0;
740
741 if (arg.flags & PTRACE_PEEKSIGINFO_SHARED)
742 pending = &child->signal->shared_pending;
743 else
744 pending = &child->pending;
745
746 for (i = 0; i < arg.nr; ) {
747 kernel_siginfo_t info;
748 unsigned long off = arg.off + i;
749 bool found = false;
750
751 spin_lock_irq(&child->sighand->siglock);
752 list_for_each_entry(q, &pending->list, list) {
753 if (!off--) {
754 found = true;
755 copy_siginfo(&info, &q->info);
756 break;
757 }
758 }
759 spin_unlock_irq(&child->sighand->siglock);
760
761 if (!found)
762 break;
763
764#ifdef CONFIG_COMPAT
765 if (unlikely(in_compat_syscall())) {
766 compat_siginfo_t __user *uinfo = compat_ptr(data);
767
768 if (copy_siginfo_to_user32(uinfo, &info)) {
769 ret = -EFAULT;
770 break;
771 }
772
773 } else
774#endif
775 {
776 siginfo_t __user *uinfo = (siginfo_t __user *) data;
777
778 if (copy_siginfo_to_user(uinfo, &info)) {
779 ret = -EFAULT;
780 break;
781 }
782 }
783
784 data += sizeof(siginfo_t);
785 i++;
786
787 if (signal_pending(current))
788 break;
789
790 cond_resched();
791 }
792
793 if (i > 0)
794 return i;
795
796 return ret;
797}
798
799#ifdef CONFIG_RSEQ
800static long ptrace_get_rseq_configuration(struct task_struct *task,
801 unsigned long size, void __user *data)
802{
803 struct ptrace_rseq_configuration conf = {
804 .rseq_abi_pointer = (u64)(uintptr_t)task->rseq,
805 .rseq_abi_size = sizeof(*task->rseq),
806 .signature = task->rseq_sig,
807 .flags = 0,
808 };
809
810 size = min_t(unsigned long, size, sizeof(conf));
811 if (copy_to_user(data, &conf, size))
812 return -EFAULT;
813 return sizeof(conf);
814}
815#endif
816
817#ifdef PTRACE_SINGLESTEP
818#define is_singlestep(request) ((request) == PTRACE_SINGLESTEP)
819#else
820#define is_singlestep(request) 0
821#endif
822
823#ifdef PTRACE_SINGLEBLOCK
824#define is_singleblock(request) ((request) == PTRACE_SINGLEBLOCK)
825#else
826#define is_singleblock(request) 0
827#endif
828
829#ifdef PTRACE_SYSEMU
830#define is_sysemu_singlestep(request) ((request) == PTRACE_SYSEMU_SINGLESTEP)
831#else
832#define is_sysemu_singlestep(request) 0
833#endif
834
835static int ptrace_resume(struct task_struct *child, long request,
836 unsigned long data)
837{
838 bool need_siglock;
839
840 if (!valid_signal(data))
841 return -EIO;
842
843 if (request == PTRACE_SYSCALL)
844 set_task_syscall_work(child, SYSCALL_TRACE);
845 else
846 clear_task_syscall_work(child, SYSCALL_TRACE);
847
848#if defined(CONFIG_GENERIC_ENTRY) || defined(TIF_SYSCALL_EMU)
849 if (request == PTRACE_SYSEMU || request == PTRACE_SYSEMU_SINGLESTEP)
850 set_task_syscall_work(child, SYSCALL_EMU);
851 else
852 clear_task_syscall_work(child, SYSCALL_EMU);
853#endif
854
855 if (is_singleblock(request)) {
856 if (unlikely(!arch_has_block_step()))
857 return -EIO;
858 user_enable_block_step(child);
859 } else if (is_singlestep(request) || is_sysemu_singlestep(request)) {
860 if (unlikely(!arch_has_single_step()))
861 return -EIO;
862 user_enable_single_step(child);
863 } else {
864 user_disable_single_step(child);
865 }
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880 need_siglock = data && !thread_group_empty(current);
881 if (need_siglock)
882 spin_lock_irq(&child->sighand->siglock);
883 child->exit_code = data;
884 wake_up_state(child, __TASK_TRACED);
885 if (need_siglock)
886 spin_unlock_irq(&child->sighand->siglock);
887
888 return 0;
889}
890
891#ifdef CONFIG_HAVE_ARCH_TRACEHOOK
892
893static const struct user_regset *
894find_regset(const struct user_regset_view *view, unsigned int type)
895{
896 const struct user_regset *regset;
897 int n;
898
899 for (n = 0; n < view->n; ++n) {
900 regset = view->regsets + n;
901 if (regset->core_note_type == type)
902 return regset;
903 }
904
905 return NULL;
906}
907
908static int ptrace_regset(struct task_struct *task, int req, unsigned int type,
909 struct iovec *kiov)
910{
911 const struct user_regset_view *view = task_user_regset_view(task);
912 const struct user_regset *regset = find_regset(view, type);
913 int regset_no;
914
915 if (!regset || (kiov->iov_len % regset->size) != 0)
916 return -EINVAL;
917
918 regset_no = regset - view->regsets;
919 kiov->iov_len = min(kiov->iov_len,
920 (__kernel_size_t) (regset->n * regset->size));
921
922 if (req == PTRACE_GETREGSET)
923 return copy_regset_to_user(task, view, regset_no, 0,
924 kiov->iov_len, kiov->iov_base);
925 else
926 return copy_regset_from_user(task, view, regset_no, 0,
927 kiov->iov_len, kiov->iov_base);
928}
929
930
931
932
933
934
935EXPORT_SYMBOL_GPL(task_user_regset_view);
936
937static unsigned long
938ptrace_get_syscall_info_entry(struct task_struct *child, struct pt_regs *regs,
939 struct ptrace_syscall_info *info)
940{
941 unsigned long args[ARRAY_SIZE(info->entry.args)];
942 int i;
943
944 info->op = PTRACE_SYSCALL_INFO_ENTRY;
945 info->entry.nr = syscall_get_nr(child, regs);
946 syscall_get_arguments(child, regs, args);
947 for (i = 0; i < ARRAY_SIZE(args); i++)
948 info->entry.args[i] = args[i];
949
950
951 return offsetofend(struct ptrace_syscall_info, entry.args);
952}
953
954static unsigned long
955ptrace_get_syscall_info_seccomp(struct task_struct *child, struct pt_regs *regs,
956 struct ptrace_syscall_info *info)
957{
958
959
960
961
962
963
964
965 ptrace_get_syscall_info_entry(child, regs, info);
966 info->op = PTRACE_SYSCALL_INFO_SECCOMP;
967 info->seccomp.ret_data = child->ptrace_message;
968
969
970 return offsetofend(struct ptrace_syscall_info, seccomp.ret_data);
971}
972
973static unsigned long
974ptrace_get_syscall_info_exit(struct task_struct *child, struct pt_regs *regs,
975 struct ptrace_syscall_info *info)
976{
977 info->op = PTRACE_SYSCALL_INFO_EXIT;
978 info->exit.rval = syscall_get_error(child, regs);
979 info->exit.is_error = !!info->exit.rval;
980 if (!info->exit.is_error)
981 info->exit.rval = syscall_get_return_value(child, regs);
982
983
984 return offsetofend(struct ptrace_syscall_info, exit.is_error);
985}
986
987static int
988ptrace_get_syscall_info(struct task_struct *child, unsigned long user_size,
989 void __user *datavp)
990{
991 struct pt_regs *regs = task_pt_regs(child);
992 struct ptrace_syscall_info info = {
993 .op = PTRACE_SYSCALL_INFO_NONE,
994 .arch = syscall_get_arch(child),
995 .instruction_pointer = instruction_pointer(regs),
996 .stack_pointer = user_stack_pointer(regs),
997 };
998 unsigned long actual_size = offsetof(struct ptrace_syscall_info, entry);
999 unsigned long write_size;
1000
1001
1002
1003
1004
1005
1006
1007 switch (child->last_siginfo ? child->last_siginfo->si_code : 0) {
1008 case SIGTRAP | 0x80:
1009 switch (child->ptrace_message) {
1010 case PTRACE_EVENTMSG_SYSCALL_ENTRY:
1011 actual_size = ptrace_get_syscall_info_entry(child, regs,
1012 &info);
1013 break;
1014 case PTRACE_EVENTMSG_SYSCALL_EXIT:
1015 actual_size = ptrace_get_syscall_info_exit(child, regs,
1016 &info);
1017 break;
1018 }
1019 break;
1020 case SIGTRAP | (PTRACE_EVENT_SECCOMP << 8):
1021 actual_size = ptrace_get_syscall_info_seccomp(child, regs,
1022 &info);
1023 break;
1024 }
1025
1026 write_size = min(actual_size, user_size);
1027 return copy_to_user(datavp, &info, write_size) ? -EFAULT : actual_size;
1028}
1029#endif
1030
1031int ptrace_request(struct task_struct *child, long request,
1032 unsigned long addr, unsigned long data)
1033{
1034 bool seized = child->ptrace & PT_SEIZED;
1035 int ret = -EIO;
1036 kernel_siginfo_t siginfo, *si;
1037 void __user *datavp = (void __user *) data;
1038 unsigned long __user *datalp = datavp;
1039 unsigned long flags;
1040
1041 switch (request) {
1042 case PTRACE_PEEKTEXT:
1043 case PTRACE_PEEKDATA:
1044 return generic_ptrace_peekdata(child, addr, data);
1045 case PTRACE_POKETEXT:
1046 case PTRACE_POKEDATA:
1047 return generic_ptrace_pokedata(child, addr, data);
1048
1049#ifdef PTRACE_OLDSETOPTIONS
1050 case PTRACE_OLDSETOPTIONS:
1051#endif
1052 case PTRACE_SETOPTIONS:
1053 ret = ptrace_setoptions(child, data);
1054 break;
1055 case PTRACE_GETEVENTMSG:
1056 ret = put_user(child->ptrace_message, datalp);
1057 break;
1058
1059 case PTRACE_PEEKSIGINFO:
1060 ret = ptrace_peek_siginfo(child, addr, data);
1061 break;
1062
1063 case PTRACE_GETSIGINFO:
1064 ret = ptrace_getsiginfo(child, &siginfo);
1065 if (!ret)
1066 ret = copy_siginfo_to_user(datavp, &siginfo);
1067 break;
1068
1069 case PTRACE_SETSIGINFO:
1070 ret = copy_siginfo_from_user(&siginfo, datavp);
1071 if (!ret)
1072 ret = ptrace_setsiginfo(child, &siginfo);
1073 break;
1074
1075 case PTRACE_GETSIGMASK: {
1076 sigset_t *mask;
1077
1078 if (addr != sizeof(sigset_t)) {
1079 ret = -EINVAL;
1080 break;
1081 }
1082
1083 if (test_tsk_restore_sigmask(child))
1084 mask = &child->saved_sigmask;
1085 else
1086 mask = &child->blocked;
1087
1088 if (copy_to_user(datavp, mask, sizeof(sigset_t)))
1089 ret = -EFAULT;
1090 else
1091 ret = 0;
1092
1093 break;
1094 }
1095
1096 case PTRACE_SETSIGMASK: {
1097 sigset_t new_set;
1098
1099 if (addr != sizeof(sigset_t)) {
1100 ret = -EINVAL;
1101 break;
1102 }
1103
1104 if (copy_from_user(&new_set, datavp, sizeof(sigset_t))) {
1105 ret = -EFAULT;
1106 break;
1107 }
1108
1109 sigdelsetmask(&new_set, sigmask(SIGKILL)|sigmask(SIGSTOP));
1110
1111
1112
1113
1114
1115
1116 spin_lock_irq(&child->sighand->siglock);
1117 child->blocked = new_set;
1118 spin_unlock_irq(&child->sighand->siglock);
1119
1120 clear_tsk_restore_sigmask(child);
1121
1122 ret = 0;
1123 break;
1124 }
1125
1126 case PTRACE_INTERRUPT:
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137 if (unlikely(!seized || !lock_task_sighand(child, &flags)))
1138 break;
1139
1140
1141
1142
1143
1144
1145
1146 if (likely(task_set_jobctl_pending(child, JOBCTL_TRAP_STOP)))
1147 ptrace_signal_wake_up(child, child->jobctl & JOBCTL_LISTENING);
1148
1149 unlock_task_sighand(child, &flags);
1150 ret = 0;
1151 break;
1152
1153 case PTRACE_LISTEN:
1154
1155
1156
1157
1158
1159
1160
1161
1162 if (unlikely(!seized || !lock_task_sighand(child, &flags)))
1163 break;
1164
1165 si = child->last_siginfo;
1166 if (likely(si && (si->si_code >> 8) == PTRACE_EVENT_STOP)) {
1167 child->jobctl |= JOBCTL_LISTENING;
1168
1169
1170
1171
1172 if (child->jobctl & JOBCTL_TRAP_NOTIFY)
1173 ptrace_signal_wake_up(child, true);
1174 ret = 0;
1175 }
1176 unlock_task_sighand(child, &flags);
1177 break;
1178
1179 case PTRACE_DETACH:
1180 ret = ptrace_detach(child, data);
1181 break;
1182
1183#ifdef CONFIG_BINFMT_ELF_FDPIC
1184 case PTRACE_GETFDPIC: {
1185 struct mm_struct *mm = get_task_mm(child);
1186 unsigned long tmp = 0;
1187
1188 ret = -ESRCH;
1189 if (!mm)
1190 break;
1191
1192 switch (addr) {
1193 case PTRACE_GETFDPIC_EXEC:
1194 tmp = mm->context.exec_fdpic_loadmap;
1195 break;
1196 case PTRACE_GETFDPIC_INTERP:
1197 tmp = mm->context.interp_fdpic_loadmap;
1198 break;
1199 default:
1200 break;
1201 }
1202 mmput(mm);
1203
1204 ret = put_user(tmp, datalp);
1205 break;
1206 }
1207#endif
1208
1209#ifdef PTRACE_SINGLESTEP
1210 case PTRACE_SINGLESTEP:
1211#endif
1212#ifdef PTRACE_SINGLEBLOCK
1213 case PTRACE_SINGLEBLOCK:
1214#endif
1215#ifdef PTRACE_SYSEMU
1216 case PTRACE_SYSEMU:
1217 case PTRACE_SYSEMU_SINGLESTEP:
1218#endif
1219 case PTRACE_SYSCALL:
1220 case PTRACE_CONT:
1221 return ptrace_resume(child, request, data);
1222
1223 case PTRACE_KILL:
1224 if (child->exit_state)
1225 return 0;
1226 return ptrace_resume(child, request, SIGKILL);
1227
1228#ifdef CONFIG_HAVE_ARCH_TRACEHOOK
1229 case PTRACE_GETREGSET:
1230 case PTRACE_SETREGSET: {
1231 struct iovec kiov;
1232 struct iovec __user *uiov = datavp;
1233
1234 if (!access_ok(uiov, sizeof(*uiov)))
1235 return -EFAULT;
1236
1237 if (__get_user(kiov.iov_base, &uiov->iov_base) ||
1238 __get_user(kiov.iov_len, &uiov->iov_len))
1239 return -EFAULT;
1240
1241 ret = ptrace_regset(child, request, addr, &kiov);
1242 if (!ret)
1243 ret = __put_user(kiov.iov_len, &uiov->iov_len);
1244 break;
1245 }
1246
1247 case PTRACE_GET_SYSCALL_INFO:
1248 ret = ptrace_get_syscall_info(child, addr, datavp);
1249 break;
1250#endif
1251
1252 case PTRACE_SECCOMP_GET_FILTER:
1253 ret = seccomp_get_filter(child, addr, datavp);
1254 break;
1255
1256 case PTRACE_SECCOMP_GET_METADATA:
1257 ret = seccomp_get_metadata(child, addr, datavp);
1258 break;
1259
1260#ifdef CONFIG_RSEQ
1261 case PTRACE_GET_RSEQ_CONFIGURATION:
1262 ret = ptrace_get_rseq_configuration(child, addr, datavp);
1263 break;
1264#endif
1265
1266 default:
1267 break;
1268 }
1269
1270 return ret;
1271}
1272
1273#ifndef arch_ptrace_attach
1274#define arch_ptrace_attach(child) do { } while (0)
1275#endif
1276
1277SYSCALL_DEFINE4(ptrace, long, request, long, pid, unsigned long, addr,
1278 unsigned long, data)
1279{
1280 struct task_struct *child;
1281 long ret;
1282
1283 if (request == PTRACE_TRACEME) {
1284 ret = ptrace_traceme();
1285 if (!ret)
1286 arch_ptrace_attach(current);
1287 goto out;
1288 }
1289
1290 child = find_get_task_by_vpid(pid);
1291 if (!child) {
1292 ret = -ESRCH;
1293 goto out;
1294 }
1295
1296 if (request == PTRACE_ATTACH || request == PTRACE_SEIZE) {
1297 ret = ptrace_attach(child, request, addr, data);
1298
1299
1300
1301
1302 if (!ret)
1303 arch_ptrace_attach(child);
1304 goto out_put_task_struct;
1305 }
1306
1307 ret = ptrace_check_attach(child, request == PTRACE_KILL ||
1308 request == PTRACE_INTERRUPT);
1309 if (ret < 0)
1310 goto out_put_task_struct;
1311
1312 ret = arch_ptrace(child, request, addr, data);
1313 if (ret || request != PTRACE_DETACH)
1314 ptrace_unfreeze_traced(child);
1315
1316 out_put_task_struct:
1317 put_task_struct(child);
1318 out:
1319 return ret;
1320}
1321
1322int generic_ptrace_peekdata(struct task_struct *tsk, unsigned long addr,
1323 unsigned long data)
1324{
1325 unsigned long tmp;
1326 int copied;
1327
1328 copied = ptrace_access_vm(tsk, addr, &tmp, sizeof(tmp), FOLL_FORCE);
1329 if (copied != sizeof(tmp))
1330 return -EIO;
1331 return put_user(tmp, (unsigned long __user *)data);
1332}
1333
1334int generic_ptrace_pokedata(struct task_struct *tsk, unsigned long addr,
1335 unsigned long data)
1336{
1337 int copied;
1338
1339 copied = ptrace_access_vm(tsk, addr, &data, sizeof(data),
1340 FOLL_FORCE | FOLL_WRITE);
1341 return (copied == sizeof(data)) ? 0 : -EIO;
1342}
1343
1344#if defined CONFIG_COMPAT
1345
1346int compat_ptrace_request(struct task_struct *child, compat_long_t request,
1347 compat_ulong_t addr, compat_ulong_t data)
1348{
1349 compat_ulong_t __user *datap = compat_ptr(data);
1350 compat_ulong_t word;
1351 kernel_siginfo_t siginfo;
1352 int ret;
1353
1354 switch (request) {
1355 case PTRACE_PEEKTEXT:
1356 case PTRACE_PEEKDATA:
1357 ret = ptrace_access_vm(child, addr, &word, sizeof(word),
1358 FOLL_FORCE);
1359 if (ret != sizeof(word))
1360 ret = -EIO;
1361 else
1362 ret = put_user(word, datap);
1363 break;
1364
1365 case PTRACE_POKETEXT:
1366 case PTRACE_POKEDATA:
1367 ret = ptrace_access_vm(child, addr, &data, sizeof(data),
1368 FOLL_FORCE | FOLL_WRITE);
1369 ret = (ret != sizeof(data) ? -EIO : 0);
1370 break;
1371
1372 case PTRACE_GETEVENTMSG:
1373 ret = put_user((compat_ulong_t) child->ptrace_message, datap);
1374 break;
1375
1376 case PTRACE_GETSIGINFO:
1377 ret = ptrace_getsiginfo(child, &siginfo);
1378 if (!ret)
1379 ret = copy_siginfo_to_user32(
1380 (struct compat_siginfo __user *) datap,
1381 &siginfo);
1382 break;
1383
1384 case PTRACE_SETSIGINFO:
1385 ret = copy_siginfo_from_user32(
1386 &siginfo, (struct compat_siginfo __user *) datap);
1387 if (!ret)
1388 ret = ptrace_setsiginfo(child, &siginfo);
1389 break;
1390#ifdef CONFIG_HAVE_ARCH_TRACEHOOK
1391 case PTRACE_GETREGSET:
1392 case PTRACE_SETREGSET:
1393 {
1394 struct iovec kiov;
1395 struct compat_iovec __user *uiov =
1396 (struct compat_iovec __user *) datap;
1397 compat_uptr_t ptr;
1398 compat_size_t len;
1399
1400 if (!access_ok(uiov, sizeof(*uiov)))
1401 return -EFAULT;
1402
1403 if (__get_user(ptr, &uiov->iov_base) ||
1404 __get_user(len, &uiov->iov_len))
1405 return -EFAULT;
1406
1407 kiov.iov_base = compat_ptr(ptr);
1408 kiov.iov_len = len;
1409
1410 ret = ptrace_regset(child, request, addr, &kiov);
1411 if (!ret)
1412 ret = __put_user(kiov.iov_len, &uiov->iov_len);
1413 break;
1414 }
1415#endif
1416
1417 default:
1418 ret = ptrace_request(child, request, addr, data);
1419 }
1420
1421 return ret;
1422}
1423
1424COMPAT_SYSCALL_DEFINE4(ptrace, compat_long_t, request, compat_long_t, pid,
1425 compat_long_t, addr, compat_long_t, data)
1426{
1427 struct task_struct *child;
1428 long ret;
1429
1430 if (request == PTRACE_TRACEME) {
1431 ret = ptrace_traceme();
1432 goto out;
1433 }
1434
1435 child = find_get_task_by_vpid(pid);
1436 if (!child) {
1437 ret = -ESRCH;
1438 goto out;
1439 }
1440
1441 if (request == PTRACE_ATTACH || request == PTRACE_SEIZE) {
1442 ret = ptrace_attach(child, request, addr, data);
1443
1444
1445
1446
1447 if (!ret)
1448 arch_ptrace_attach(child);
1449 goto out_put_task_struct;
1450 }
1451
1452 ret = ptrace_check_attach(child, request == PTRACE_KILL ||
1453 request == PTRACE_INTERRUPT);
1454 if (!ret) {
1455 ret = compat_arch_ptrace(child, request, addr, data);
1456 if (ret || request != PTRACE_DETACH)
1457 ptrace_unfreeze_traced(child);
1458 }
1459
1460 out_put_task_struct:
1461 put_task_struct(child);
1462 out:
1463 return ret;
1464}
1465#endif
1466